Rae, 64, is stepping down to fully focus on his role as chief negotiator for First Nations in Ontario in talks with the provincial government about how aboriginals can benefit from the resource-rich “Ring of Fire”mining area, a job he officially assumed last month.

Rae said it became clear that it was impossible to perform that role and continue his duties as a member of Parliament, leading him to make the “tough decision” to step down as the MP for Toronto Centre.

“As time goes on, this is going to be a major undertaking, and that really means that I have to step down, either step down from that job or step down as a member of Parliament,” he said. “It’s been a very difficult decision … and quite an emotional one for me.”

It was not known what his last day on the job would be.

Rae served as interim Liberal leader from May 2011 until April 2013, when Justin Trudeau was elected party leader. His departure is seen by some as a blow for the Liberal caucus, which loses his decades of political experience and heavyweight presence in the House of Commons. The Liberals also recently lost Montreal area MP Denis Coderre, another experienced parliamentarian who is taking a run at municipal politics.

Trudeau told reporters he was “sad” that Rae was leaving but said his work with aboriginals was “extremely important.

“We will miss his wise counsel, we will miss his wisdom and experience, but we will miss mostly his passion, his emotion, his very, very human dedication to wearing his heart on his sleeve and his love for his country for all to see,” Trudeau said.

Trudeau also said history will remember Rae as a great leader for the Liberal party during a difficult time, and that he will continue to be a “valued friend and ally and resource for all Liberals in this country.

“I am not letting him go far.”

Rae said that he’s “more than confident” that Trudeau will become prime minister of Canada and pledged to provide any assistance necessary to the party and do everything he can to ensure the political success of the Liberal party of Canada.

“I have thoroughly enjoyed my time with him and I deeply regret that I will not be going the rest of the journey with him,” he said. “But I hope that I have been able in my own way, in the last few years, to help to create the conditions in the party that have strengthened our position.”

The other party leaders wished Rae well.

“I would like to commend @bobraeMP for his many years of public service to Canadians,” Prime Minister Stephen Harper tweeted Wednesday morning. “I wish him best of luck with future endeavours.”

NDP leader Tom Mulcair also wished Rae and his family well.

Rae, an outspoken advocate for aboriginal rights, is an experienced lawyer and mediator.

He was an NDP member of Parliament from 1978 to 1982 before moving to provincial politics. He was the NDP Ontario premier from 1990 to 1995. He sought the federal Liberal leadership in 2006, but lost to Stephane Dion. He took the interim leader job after the 2011 election which saw the Liberals drop to 34 seats in the House of Commons, the fewest in their history.

Rae said his decision to step down is not about money, and that he hasn’t been paid for his work in the North. Rather, it became clear that he wouldn’t have time to do both jobs.

“This is really about time and about how can I effectively serve the interests of the people I’ve been asked to serve and at the same time stay on as an MP, and it simply wasn’t possible.”

But Rae stopped short of saying whether this decision marks the end of his political career.

“Never say never, but it certainly closes the door for now.”

Rae’s new position involved representing First Nation interests in Ontario’s multibillion-dollar Ring of Fire mineral development project, about 540 kilometres northeast of Thunder Bay.

Thought to be one of the most promising mineral development opportunities in Ontario in decades, the Ring of Fire is home to major chromite, copper, nickel, zinc, gold and kimberlite deposits.

The chromite deposit is the largest ever discovered in North America — with the commercially valuable mineral a key ingredient in creating stainless steel. Estimates put total revenues for the Ring of Fire at as much as $50 billion.
First Nations in the lowlands west of St. James Bay have expressed concerns about mining exploration in the region. They insist that they receive a fair portion of the resource revenues and be adequately consulted on the matter.

Rae will tour the nine First Nations in the next few months to meet with community members.

Bob Rae’s Full Statement

Some months ago I agreed to work with the Matawa Tribal Council in northern Ontario as their negotiator in dealings with the government of Ontario.

The Ring of Fire mining development will have a huge impact on the communities in the area and well beyond. How positive that impact could be has yet to be determined, and will depend on the outcome of the discussions that are now underway, and will only intensify in the time ahead.

It has become clear to me that the full scope of the negotiator’s job is no longer compatible with my also serving as a member of Parliament. And so I face a choice.

I have decided to return to my profession as a lawyer and mediator, to continue working for the Matawa Tribal Council, and to step down as the Member of Parliament for Toronto Centre.

This has been a difficult personal decision. I was first elected to Parliament in 1978, and was deeply honoured to have had the chance to serve again these past five years, as well as to lead the Liberal Party at a time of change and renewal. I have made wonderful friendships, and am so proud of the renewal and rebuilding that has been accomplished over the last few years. I’m leaving the party in confidence that the party is in good shape.

I am especially happy that as interim leader I was able to champion aboriginal issues, and share the importance of mental health with my colleagues. I also particularly enjoyed having the confidence of Stephane Dion, Michael Ignatieff and Justin Trudeau as foreign affairs spokesman for the Liberal Party. I shall miss this work very much.

I want to thank my constituents in Toronto Centre, my colleagues and friends in the Liberal Party and all parties in Parliament, my leader, Justin Trudeau, and the people of Canada for giving me the chance to serve. It has been an honour and a pleasure.

Helping to improve the life of First Nations people has been a longstanding commitment of mine, and this opportunity to serve is one I felt I could not decline.

I have told Mr. Trudeau and my colleagues that I shall continue to work for the Liberal Party, and I look forward to remaining engaged in Canadian public life.